Bring back queue safety of statement iteration.
Bring back queue safety of statement iteration.

carabina/GRDB.swift,zmeyc/GRDB.swift,carabina/GRDB.swift,zmeyc/GRDB.swift,groue/GRDB.swift,groue/GRDB.swift,zmeyc/GRDB.swift,groue/GRDB.swift,groue/GRDB.swift,zmeyc/GRDB.swift